Caster attachment system

ABSTRACT

A caster attachment system includes an upper section and a lower section. The upper section mounts to a piece of equipment. The lower section provides a post for the mounting of a caster. A shaped key on the lower section fits within a receiver socket on the upper portion. The upper section and the lower section are held together by a threadable connection.

FIELD

The present invention pertains to casters; more particularly, the present invention pertains to a caster attachment system used with a medical/surgical system such as a vitrectomy system.

BACKGROUND

In prior art medical/surgical systems, the interface between a directional caster and a supported structure was typically done with a keyed caster that extended through the structure and was secured with a locking nut disposed within the system. It has been found that some designs of equipment will not provide sufficient access to secure a caster with a locking nut in this manner. In addition, such a locking nut makes it more difficult for field service personnel to assemble and service equipment at the customer site. There is therefore a need in the art for a caster attachment system that will allow the caster to be easily secured from the outside of the system.

SUMMARY

The disclosed caster attachment system enables a caster to be secured to a piece of equipment from the outside using just a simple wrench.

The disclosed caster attachment system includes an upper section and a lower section. The upper section is connectable to the bottom of a piece of medical/surgical equipment. The upper section further includes a shaped opening formed therein and externally formed threads surrounding the shaped opening.

The lower section includes a caster mounting post. Substantially aligned with the caster mounting post is a shaped key member. A floating nut engages a collar surrounding the shaped key member.

By threadably connecting the floating nut to the externally formed threads on the upper section and tightening the connection with a wrench, the caster is secured to the piece of equipment.

BRIEF DESCRIPTION OF THE DRAWING FIGURE

A better understanding of the caster attachment system of the present invention may be had by reference to the drawing figure, wherein:

FIG. 1 is a perspective view of the disclosed caster attachment system.

DESCRIPTION OF THE EMBODIMENTS

The caster attachment system 10 for use with a medical/surgical system such as a vitrectomy system provides an alternative method for attaching and removing casters 100. The disclosed caster attachment system 10 allows directional locking casters to be secured to the supported structure from the exterior of the medical/surgical system.

As shown in FIG. 1, the attachment fitting used in the disclosed caster attachment system 10 includes two separate portions 20, 40. The first portion 20 is mounted to the bottom exterior of the medical/surgical equipment.

The first or top portion 20 of the caster attachment system 10 includes a receiver socket 22. Surrounding the receiver socket 22 is an externally threaded portion 24 to interface with the floating nut 44 explained below. The receiver socket 22 is secured to the supported piece of medical/surgical equipment with a threaded interface 25 or it can be mounted using nuts 28, bolts, pins, insert molded or a cast in feature. Mating anti-rotation features prevent rotation of the second or lower portion 40 with respect to the upper portion 20. Such features may preferably include a machined key feature wherein the machined key and its mating socket have at least one flat side; a set of pins passing through an aligned set of holes 30, 50; and/or fasteners.

The second or bottom portion 40 of the caster attachment system 10 includes a caster post 42 attached to the caster 100. The caster post 42 is secured to the upper portion 20 using a captive nut 44. The floating nut 44 is trapped just above the caster post 42. The inner diameter of the nut 44 is larger than the outer diameter of the shaft 42. This difference in diameters allows the captive nut 44 to float about shaft 42 and to accommodate any misalignments. A flange 46 is formed around the caster mounting post 42 of the lower portion 40 for contact with the interior of the floating nut 44. Above the flange 46 is the male portion or key 48 which fits into the receiver socket 22.

The disclosed caster attachment system takes up very little space. A simple wrench selected to fit on floating nut 44 is used to couple and decouple the unit from the supported medical/surgical equipment. Those of ordinary skill in the art will understand that the caster attachment system may be accessed from the outside of the supported system and a minimum of parts are used.

As may be seen by the foregoing, a receiver socket 22 is used with an integrated threaded fastening system and a matching keyed pin with a floating nut. The receiver socket portion 22 of the caster attachment system can either be mechanically attached with a nut 28, or the receiver socket 22 can be insert molded. When the two 

1. A caster system for attaching to a medical/surgical system, said caster system comprising: an upper portion including: a receiver socket with an external thread; a mounting for attachment to the medical/surgical system; a lower portion including: a key constructed and arranged for non-rotational interfitment into said receiver socket, a captive internally threaded nut, and a caster post; a caster constructed and arranged for attached to said caster post; whereby when said upper portion and said lower portion are brought together, said key is located within said receiver socket and said captive internally threaded nut threadably engages said external threads on said receiver socket.
 2. The caster system as defined in claim 1 wherein said key has at least one flat side.
 3. The caster system as defined in claim 1 herein said receiver socket has at least one flat side.
 4. A caster attachment device comprising: a lower section, said lower section including: a caster mounting post; an internally threaded nut surrounding said caster mounting post; a male key section substantially aligned with said caster mounting post; a male key section substantially aligned with said caster mounting post; an upper section, said upper section including: a top connector; a bottom externally threaded region; and a female receiver section constructed and arranged to receive said male key section; whereby said lower section may be connected to said upper section by inserting said male key section into said female receiver section.
 5. The caster attachment device as defined in claim 2 further including a rotation preventing lock between said lower section and said upper section.
 6. The caster attachment device as defined in claim 2 wherein said internally threaded nut engages said externally threaded region.
 7. A method for attaching casters to a medical/surgical system, said method comprising the stops of: affixing a shaped receiver socket to the bottom of the piece of medical/surgical equipment; inserting a key attached to a caster mounting post into said shaped receiver socket; securing said insertion of said key into said receiver socket by threadably engaging a nut surrounding said key to external threads formed around said shaped receiver socket; and attaching a caster to said caster mounting post.
 8. The method as defined in claim 7 further including the step of locking said key and said shaped socket together before threadably securing them together. 